When a genetic analyzer is used to determine the base sequence of DNA, four time-series data sets corresponding to four kinds of bases, A (adenine), G (guanine), C (cytosine), and T (thymine) are obtained.
According to a conventional base sequence determination method such as a method using Phred, prior to peak detection, preprocessing including noise elimination and mobility correction is performed on these time-series data sets. Mobility correction is performed to correct the deviation among the time-series data sets caused by a difference in migration speed among dyes used to label four kinds of bases. Then, peak detection is performed to determine peaks with a large peak height or a large peak area as the peaks of bases (see Non-Patent Document 1).
In measurement using electrophoresis, signal characteristics are widely changed among the initial, middle, and final stages of migration. Based on this fact, one of the present inventors has proposed a noise elimination method in which electrophoretic data is separated into some parts and noise elimination is performed on each of the parts in consideration of such a change in signal characteristics (see Patent Document 1).
Further, when a genetic analyzer is used to detect respective peaks of four kinds of bases in chronological order, there is a case where peak appearance time relatively deviates due to, for example, a difference in migration speed among dyes used to label four kinds of bases. In order to correct the deviation of peak appearance time, one of the present inventors has also proposed a method in which time-series signals are shifted with respect to one another so that the total area of portions where detected peaks overlap each other is minimized (see Patent Document 2).    Non-Patent Document 1: Ewing B, Hillier L, Wendl M, Green P: Base-calling of automated sequencer traces using phred. I. Accuracy assessment. Genome Research 8:175-185, 1998    Patent Document 1: Japanese Patent Application Laid-open No. 2002-202286    Patent Document 2: Japanese Patent Application Laid-open No. 2002-228633